Vehicle sand rolling simulation method

Abstract

The invention provides a sand rolling simulation method for a vehicle. The method comprises the following steps: firstly, constructing a sand simulation model based on a smoothed particle fluid dynamics algorithm; secondly, acquiring and benchmarking a simulation curve and a test curve, and reversely solving performance parameters of the sand simulation model; thirdly, acquiring a critical rolling angle of the vehicle on the static rolling test device; then, the performance parameters are substituted into the whole vehicle sand rolling model, the initial speed of the vehicle is adjusted for simulation, simulation data are obtained, when the deviation between the vehicle body rolling angle obtained through simulation and the critical rolling angle conforms to a preset range, it is judged that the state is a rolling critical state, and the corresponding vehicle critical initial speed is output; finally, the critical initial speed of the vehicle is used for a real vehicle test, test data are obtained, and if the deviation between the test data and simulation data exceeds a verification threshold value, model parameters are corrected. The model reuse rate can be effectively improved, the repeated development cost is reduced, and an efficient technical scheme is provided for safe development of vehicle sand rolling.

Description

Technical Field

[0001] This invention relates to the field of automotive computer-aided engineering, and more particularly to a method for simulating vehicle rolling over in sand. Background Technology

[0002] With the rapid development of the automotive industry, occupant safety has become one of the most important performance indicators for evaluating vehicles, and various consumer testing procedures are increasingly stringent in their requirements for vehicle crash safety. Since 2021, the sales and ownership of SUVs in the Chinese market have been growing rapidly. Due to the higher center of gravity of SUVs, they are more prone to rollover accidents. As the number of SUVs continues to increase in recent years, the proportion of such accidents will continue to rise. Vehicle rollover is a type of accident with a very high fatality rate. In 2015, the average number of deaths caused by single-vehicle rollover accidents (including those that plunge off cliffs) in China was 0.71. Among these, "tripping" is the most common form of single-vehicle rollover accident, accounting for 33.82%, and rollovers on sand can account for more than 90% of tripping accidents.

[0003] In real-vehicle safety development testing, a distinct "critical rollover" state exists, representing the dynamic critical point between stable driving and complete loss of control rollover. Accurately reproducing and controlling this critical state is a core prerequisite for effectively verifying vehicle rollover resistance, calibrating electronic stability systems, and optimizing passive safety design. However, the key test parameters corresponding to this critical state (such as initial velocity and impact angle) are difficult to determine directly through theoretical calculations or experience. Without reliable simulation prediction methods, it is necessary to rely on repeated trial and error in the real-vehicle phase to approximate the state, resulting in lengthy development cycles, high costs, and poor consistency and controllability of results.

[0004] In existing simulation technology solutions, the industry largely relies on proprietary commercial software modules provided by a few foreign suppliers for dynamic modeling of complex media such as sandy terrain. These solutions are not only costly to purchase and maintain, but their core technologies are also usually closed, resulting in insufficient autonomy for automakers in calibrating key parameters, modifying characteristics, and iterating technologies in simulation models. This makes it difficult to build independent, controllable, and efficient simulation capabilities, thus hindering the rapid and positive development of vehicle safety performance. Summary of the Invention

[0005] The purpose of this invention is to provide a vehicle rollover simulation method in sand, which can improve the success rate of tests and reduce development costs through sand modeling, critical state prediction, parameter output, and benchmarking and optimization with real vehicles.

[0006] To achieve the above objectives, the present invention provides a method for simulating vehicle rollover on sand, comprising the following steps:

[0007] Step S1: Construct a sand simulation model based on the smooth particle hydrodynamics algorithm;

[0008] Step S2: Establish a simulation scenario of the trolley model impacting the sandy surface, obtain the simulation curve, obtain the test curve by comparing it with the trolley impacting the sandy test scenario, compare the simulation curve and the test curve, and obtain the performance parameters of the sandy simulation model in reverse.

[0009] Step S3: Obtain the critical roll angle of the vehicle on the static roll test device;

[0010] Step S4: Substitute the performance parameters into the whole vehicle sand rollover model, adjust the initial vehicle speed for simulation, obtain simulation data, and when the deviation between the simulated vehicle rollover angle and the critical rollover angle is within the preset range, determine that the current working condition is the critical rollover state, and output the corresponding critical initial vehicle speed.

[0011] Step S5: Apply the critical initial velocity of the vehicle to a real vehicle rolling test on sand to obtain test data. If the deviation between the test data and the simulation data exceeds the verification threshold, the performance parameters of the sand simulation model are corrected.

[0012] In one embodiment of the present invention, the performance parameters of the sand simulation model include shear modulus, yield strength and tangent modulus.

[0013] In one embodiment of the present invention, step S2 specifically includes:

[0014] Step S21: Simulate the impact of the trolley on the sand surface at various preset speeds to obtain the simulation-acceleration curves;

[0015] Step S22: Obtain the acceleration collected by the acceleration sensor equipped on the tire of the test trolley, and obtain the test-acceleration curve;

[0016] Step S23: Compare the simulation-acceleration curve with the experimental-acceleration curve, and calculate the consistency index between the two;

[0017] Step S24: If the consistency index does not reach the preset threshold, adjust the performance parameters of the sand simulation model and recalculate until the preset threshold is reached.

[0018] In one embodiment of the present invention, in step S21, the various preset speeds include 20km / h, 25km / h, 30km / h and 35km / h.

[0019] In one embodiment of the present invention, in step S23, the consistency index is calculated using the ISO18571 standard, and the preset threshold is 0.75; when the ISO18571 score reaches 0.75 or above, the reverse calibration of the macroscopic mechanical properties of the sandy land is considered to be completed.

[0020] In one embodiment of the present invention, in step S24, the performance parameters include shear modulus, yield strength and tangent modulus;

[0021] The adjustment of the performance parameters of the sand simulation model specifically includes: adjusting the shear modulus, yield strength, and tangent modulus of the sand model in response to deviations in the acceleration curve.

[0022] In one embodiment of the present invention, step S3 specifically includes:

[0023] Step S31: Place the vehicle on the static rollover test device;

[0024] Step S32: The control device slowly increases the tilt angle until the vehicle rolls over;

[0025] Step S33: Record the device angle at the moment the vehicle rolls over, and define it as the critical roll angle.

[0026] In one embodiment of the present invention, the preset range in step S4 is within 10 degrees. When the error between the simulated vehicle roll angle and the critical roll angle is within 10 degrees, it is confirmed that the critical roll condition has been reached.

[0027] In one embodiment of the present invention, in step S5,

[0028] The simulation data includes the simulated vehicle's roll start position, roll stop position, and roll angle;

[0029] The test data includes the roll start position, roll stop position, and roll angle of the test vehicle;

[0030] The verification threshold is within 10 degrees. If the deviation between the experimental data and the simulation data is within 10 degrees, the accuracy of the sand simulation model is confirmed. If the deviation between the experimental data and the simulation data exceeds 10 degrees, the performance parameters of the sand simulation model are corrected.

[0031] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method described above.

[0032] This invention offers the following advantages: By constructing a vehicle-sand coupling model and combining it with pre-simulation prediction of rollover critical states, this invention effectively reduces aimless real-vehicle testing, significantly lowering development costs and resource consumption. Simultaneously, by independently establishing a sand dynamics model based on the SPH algorithm, it eliminates dependence on external suppliers' sand simulation modules, achieving independent control over core technologies. The constructed sand model possesses good versatility and scalability, and has been successfully applied in multiple vehicle models under development. It can quickly adapt to different vehicle models and sand conditions, significantly improving model reusability and reducing repetitive development costs. Furthermore, this invention greatly reduces the number of real-vehicle verifications, significantly shortening the development cycle, saving test vehicle resources, and significantly improving the systematicness and reliability of rollover safety development. In summary, this invention provides an efficient and reusable vehicle sand rollover simulation method, forming a closed-loop technology process from sand modeling, critical state prediction, test parameter optimization to real-vehicle benchmarking verification. It has been successfully applied in the development of multiple new energy vehicle models, significantly enhancing enterprises' independent development capabilities for high-risk rollover conditions. Attached Figure Description

[0033] Figure 1 A flowchart of a vehicle rolling simulation method in sandy terrain according to an embodiment of the present invention is disclosed;

[0034] Figure 2 The present invention discloses a simulation diagram of a vehicle rolling simulation method on sand at different preset speeds, illustrating the impact of a trolley on the sand surface.

[0035] Figure 3 The simulation-experiment acceleration curve comparison diagram of a vehicle rollover simulation method in sandy terrain according to an embodiment of the present invention is disclosed.

[0036] Figure 4 The diagram shows the vehicle body-ground angle-time calibration curve of a vehicle rolling simulation method in sand according to an embodiment of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0038] A method for simulating vehicle rolling over in sand, such as Figure 1 As shown, it includes the following steps:

[0039] Step S1: Construct a sand simulation model based on the Smoothed Particle Hydrodynamics algorithm. Preferably, in this embodiment, Smoothed Particle Hydrodynamics (SPH) is a meshless Lagrangian particle method for numerical simulation. Its process involves discretizing the continuous medium to be simulated (such as a fluid, solid, or deformable material like sand) into a series of "particles" with physical properties such as mass, density, and velocity. A mathematical tool called a smoothing kernel function is then used to calculate the interactions between these particles and the evolution of their physical quantities.

[0040] Step S2: Establish a simulation scenario of the trolley model impacting the sandy surface, obtain the simulation curve, and obtain the test curve by comparing it with the trolley impacting the sandy test scenario. Compare the simulation curve and the test curve to obtain the performance parameters of the sandy simulation model. In this embodiment, preferably, the trolley is a standard trolley model, and the tires of the standard trolley model are equipped with acceleration sensors.

[0041] Step S3: Obtain the critical roll angle of the vehicle on the static roll test device.

[0042] Step S4: Substitute the performance parameters into the whole vehicle sand rollover model, adjust the initial vehicle speed for simulation, and obtain simulation data. When the deviation between the simulated vehicle rollover angle and the critical rollover angle is within the preset range, determine that the current working condition is the critical rollover state, and output the corresponding critical initial vehicle speed.

[0043] Step S5: Apply the vehicle's critical initial velocity to a real vehicle rollover test on sand to obtain test data. If the deviation between the test data and the simulation data exceeds the verification threshold, then the performance parameters of the sand simulation model are corrected.

[0044] In this embodiment, the performance parameters of the sand simulation model include shear modulus, yield strength, and tangent modulus. Preferably, the shear modulus is 0.001, the yield strength is 1.9E-9, and the tangent modulus is 1.9E-9.

[0045] In this embodiment, step S2 specifically includes:

[0046] like Figure 2 As shown, step S21: Simulate the impact of the trolley on the sand surface at various preset speeds to obtain the simulation-acceleration curve;

[0047] Step S22: Obtain the acceleration collected by the acceleration sensor equipped on the tire of the test trolley, and obtain the test-acceleration curve;

[0048] Step S23: Compare the simulation-acceleration curve with the experimental-acceleration curve, and calculate the consistency index between the two;

[0049] Step S24: If the consistency index does not reach the preset threshold, adjust the performance parameters of the sand simulation model and recalculate until the preset threshold is reached. In this preferred embodiment, as follows... Figure 3 As shown, by comparing the simulation-acceleration curves and the experimental-acceleration curves, the consistency index between the two was calculated, and the result was ISO18571: 0.768. Since ISO18571: 0.768 > ISO18571: 0.75, the reverse calibration of the macroscopic mechanical properties of the sandy land is considered complete.

[0050] In this embodiment, in step S21, the various preset speeds include 20km / h, 25km / h, 30km / h and 35km / h.

[0051] In this embodiment, in step S23, the consistency index is calculated using the ISO 18571 standard, with a preset threshold of 0.75. When the ISO 18571 score reaches 0.75 or higher, the reverse calibration of the macroscopic mechanical properties of the sand is considered complete. Preferably, ISO 18571 is an international technical specification specifically used to objectively evaluate the correlation between automotive simulation models and physical test results. It is mainly used to calculate the correlation coefficient between simulation signals and test signals, thereby quantifying the accuracy of the model.

[0052] In this embodiment, step S24 involves adjusting the performance parameters of the sand simulation model, specifically including: adjusting the shear modulus, yield strength, and tangent modulus of the sand simulation model in response to deviations in the acceleration curve.

[0053] In this embodiment, step S3 specifically includes:

[0054] Step S31: Place the vehicle on the static rollover test device. Preferably, in this embodiment, the static rollover test device causes the vehicle to tilt slowly and smoothly around the rollover axis. The rollover axis is typically the line connecting the wheel contact points.

[0055] In step S32, the control device gradually increases the tilt angle until the vehicle rolls over. Preferably, in this embodiment, a tilt sensor monitors the angle between the vehicle body and the horizontal ground in real time.

[0056] Step S33: Record the device angle at the moment the vehicle rolls over, and define it as the critical roll angle. Preferably, in this embodiment, when the tilt angle increases to a certain instant, and the vehicle begins irreversible rollover due to its center of gravity crossing the support boundary, immediately record the platform tilt angle at that moment. This platform tilt angle is the critical roll angle.

[0057] In this embodiment, the preset range in step S4 is within 10 degrees. When the error between the simulated vehicle roll angle and the critical roll angle is within 10 degrees, it is confirmed that the critical roll condition has been reached.

[0058] In this embodiment, the simulation data includes the simulated vehicle's rollover start position, rollover stop position, and vehicle rollover angle. The test data includes the test vehicle's rollover start position, rollover stop position, and vehicle rollover angle.

[0059] In this preferred embodiment, the vehicle rollover angle is used as the core verification indicator in the real-vehicle sand rollover test. The angle difference between the simulated and experimental rollover angle curves at the same time point is calculated from the start of the rollover to the first contact with the ground. If the angle difference at all key time points is within ±10 degrees, the accuracy of the vehicle sand rollover coupling model is deemed satisfactory and can be used for subsequent safety performance analysis. Furthermore, the vehicle rollover angle is the angle between the vehicle body and the ground. Further, the rollover start and stop positions of the simulated and experimental vehicles are compared using animation to obtain the judgment results.

[0060] The verification threshold is within 10 degrees. If the deviation between the experimental data and the simulation data is within 10 degrees, the accuracy of the sand simulation model is confirmed; if the deviation exceeds 10 degrees, the performance parameters of the sand simulation model are corrected. In this preferred embodiment, as... Figure 4 As shown, the horizontal axis represents time in milliseconds (ms), ranging from 0 to 2000; the vertical axis represents angle in degrees (°), ranging from 0 to 90. Solid black lines represent experimental data, and dashed gray lines represent simulation data. Three state intervals are marked on the left side of the vertical axis, representing the vehicle's state: Definitely rollover: angle > 70°; Critical rollover: angle 50°–70°; Definitely not rollover: angle < 50°. The experimental-vehicle-ground angle curve and the simulated-vehicle-ground angle curve show a consistent trend, and the deviation between the experimental and simulated data is within 10 degrees. The peak vehicle tilt angles of both curves are between 50° and 70°, falling within the critical rollover region, reflecting that the vehicle is in a critical rollover state.

[0061] In this embodiment, an electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the method described above.

[0062] In one embodiment of this invention, traditional trial-and-error methods require at least three trials to explore the relationship between the vehicle's initial velocity and roll angle, followed by approximately three more trials to approach the critical state, accumulating to more than six real-vehicle tests. This invention utilizes simulation to directly establish the relationship between initial velocity and roll angle, saving on preliminary exploratory tests. After model calibration, the optimized sand parameters can be directly used in subsequent projects, significantly improving the accuracy and success rate of the initial test setup, reducing the total number of tests from more than six to approximately three, significantly saving time, vehicle, and manpower costs. Furthermore, engineers can accurately analyze the intrusion into the passenger compartment, the locking timing of seat belts, and the deployment timing of airbags in a virtual environment, thereby scientifically optimizing various parameters of the restraint system. This optimization based on reliable simulation data can reduce the risk of injury to critical parts of the occupant's head and neck in accidents, improving the vehicle's passive safety performance.

[0063] The technical objective of this invention is to establish a sand model using the SPH algorithm to simulate non-rigidity, deformability, and fluidity. In the conceptual design phase, a trolley is used to impact the sand, and the simulation curves are compared with the test curves to calculate the sand's performance parameters, avoiding complex full-vehicle testing and obtaining the sand's dynamic characteristics. These sand performance parameters are then substituted into the vehicle's sand rollover model to obtain a simulation result close to the critical rollover state. In the testing phase, test settings are made based on the simulation data, and the parameters are further optimized based on the benchmark model, reducing the number of tests and significantly lowering costs. Furthermore, this finite element sand model and method can be used in other development projects. The technical conclusion of this invention is that it provides an efficient and reusable vehicle sand rollover simulation method, realizing a closed-loop process from sand modeling, critical state prediction, parameter output to real-vehicle benchmarking and optimization. This method has been successfully applied in the development of multiple new energy vehicle models, significantly improving enterprises' independent development capabilities for high-risk rollover conditions, and has broad application prospects and promotional value.

[0064] This invention offers the following advantages: By constructing a vehicle-sand coupling model and combining it with pre-simulation prediction of rollover critical states, this invention effectively reduces aimless real-vehicle testing, significantly lowering development costs and resource consumption. Simultaneously, by independently establishing a sand dynamics model based on the SPH algorithm, it eliminates dependence on external suppliers' sand simulation modules, achieving independent control over core technologies. The constructed sand model possesses good versatility and scalability, and has been successfully applied in multiple vehicle models under development. It can quickly adapt to different vehicle models and sand conditions, significantly improving model reusability and reducing repetitive development costs. Furthermore, this invention greatly reduces the number of real-vehicle verifications, significantly shortening the development cycle, saving test vehicle resources, and significantly improving the systematicness and reliability of rollover safety development. In summary, this invention provides an efficient and reusable vehicle sand rollover simulation method, forming a closed-loop technology process from sand modeling, critical state prediction, test parameter optimization to real-vehicle benchmarking verification. It has been successfully applied in the development of multiple new energy vehicle models, significantly enhancing enterprises' independent development capabilities for high-risk rollover conditions.

[0065] The embodiments described above are merely further illustrations of the present invention and are not intended to limit the present invention in any other way. The present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding modifications and changes based on the present invention, but all such modifications and changes should fall within the protection scope of the present invention.

Claims

1. A method for simulating vehicle rolling over in sand, characterized in that, Includes the following steps: Step S1: Construct a sand simulation model based on the smooth particle hydrodynamics algorithm; Step S2: Establish a simulation scenario of the trolley model impacting the sandy surface, obtain the simulation curve, obtain the test curve by comparing it with the trolley impacting the sandy test scenario, compare the simulation curve and the test curve, and obtain the performance parameters of the sandy simulation model in reverse. Step S3: Obtain the critical roll angle of the vehicle on the static roll test device; Step S4: Substitute the performance parameters into the whole vehicle sand rollover model, adjust the initial vehicle speed for simulation, obtain simulation data, and when the deviation between the simulated vehicle rollover angle and the critical rollover angle is within the preset range, determine that the current working condition is the critical rollover state, and output the corresponding critical initial vehicle speed. Step S5: Apply the critical initial velocity of the vehicle to a real vehicle rolling test on sand to obtain test data. If the deviation between the test data and the simulation data exceeds the verification threshold, the performance parameters of the sand simulation model are corrected.

2. The vehicle rollover simulation method according to claim 1, characterized in that, The performance parameters of the sand simulation model include shear modulus, yield strength, and tangent modulus.

3. The vehicle rollover simulation method according to claim 1, characterized in that, Step S2 specifically includes: Step S21: Simulate the impact of the trolley on the sand surface at various preset speeds to obtain the simulation-acceleration curves; Step S22: Obtain the acceleration collected by the acceleration sensor equipped on the tire of the test trolley, and obtain the test-acceleration curve; Step S23: Compare the simulation-acceleration curve with the experimental-acceleration curve, and calculate the consistency index between the two; Step S24: If the consistency index does not reach the preset threshold, adjust the performance parameters of the sand simulation model and recalculate until the preset threshold is reached.

4. The vehicle rollover simulation method according to claim 3, characterized in that, In step S21, the various preset speeds include 20km / h, 25km / h, 30km / h and 35km / h.

5. The vehicle rollover simulation method according to claim 3, characterized in that, In step S23, the consistency index is calculated using the ISO18571 standard, and the preset threshold is 0.75; when the ISO18571 score reaches 0.75 or above, the reverse calibration of the macroscopic mechanical properties of the sandy land is considered complete.

6. The vehicle rollover simulation method according to claim 3, characterized in that, In step S24, the performance parameters include shear modulus, yield strength, and tangent modulus; The adjustment of the performance parameters of the sand simulation model specifically includes: adjusting the shear modulus, yield strength, and tangent modulus of the sand model in response to deviations in the acceleration curve.

7. The vehicle rollover simulation method according to claim 1, characterized in that, Step S3 specifically includes: Step S31: Place the vehicle on the static rollover test device; Step S32: The control device slowly increases the tilt angle until the vehicle rolls over; Step S33: Record the device angle at the moment the vehicle rolls over, and define it as the critical roll angle.

8. The vehicle rollover simulation method according to claim 1, characterized in that, The preset range in step S4 is within 10 degrees. When the error between the simulated vehicle roll angle and the critical roll angle is within 10 degrees, the critical roll condition is confirmed to have been reached.

9. A vehicle rollover simulation method in sand as described in claim 1, characterized in that, In step S5, The simulation data includes the simulated vehicle's roll start position, roll stop position, and roll angle; The test data includes the roll start position, roll stop position, and roll angle of the test vehicle; The verification threshold is within 10 degrees. If the deviation between the experimental data and the simulation data is within 10 degrees, the accuracy of the sand simulation model is confirmed. If the deviation between the experimental data and the simulation data exceeds 10 degrees, the performance parameters of the sand simulation model are corrected.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the program to implement the method as described in any one of claims 1 to 9.

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